ES2201257T3 - FUEL INJECTION POST FOR A STRAIGHT REACTOR COOLED BY TRANSPIRATION. - Google Patents

Abstract

THIS INVENTION REFERS TO A FUEL INJECTION MASTER (6) FOR A STATORREACTOR (1), WHICH INCLUDES A STRAVE (7) PROVIDED WITH AN ATTACK EDGE (8). IN ACCORDANCE WITH THE INVENTION, LESS THAN THE PROXIMITIES OF YOUR ATTACK EDGE (8), BY A PERMEABLE WALL (12) AND MAGAZINE IN THE CONCAVITY OF THE SUCH PERMEABLE WALL (12) OF THE ESTRAVE (7), AND INJECTION MEANS ( 15, 18) OF A REFRIGERATION FLUID IN THIS CHAMBER, SO THAT THROUGH THE PERMEABLE WALL CITED (12).

Description

Fuel injection post for a statorreactor cooled by perspiration.

The present invention relates to a post of fuel injection for a statorreactor that works in a Wide range of Mach number, particularly in a Mach number high, for example of the order of 12 to 15.

It is known that, for aircraft propulsion hypersonic (missiles, devices, airplanes, etc ...), the Statorreactors are particularly advantageous, since they allow that works with a wide range of Mach number, for example from 2 to 15, and have a specific reduced consumption of fuel. Depending on the particular application to an aircraft and eventually from the flight phase of the latter, the fuel used can be a liquid hydrocarbon, such as kerosene for example, or a gas, such as hydrogen or methane by example.

It is also known that a statorreactor behaves, on the one hand, at least one oxidizer inlet, constituted more usually by an air sleeve or an air outlet, which directs a jet of oxidizer (particularly air) into a chamber of combustion and, on the other hand, at least one injection device allowing the fuel to be injected into said jet of oxidizer, so that a mixture flow is obtained oxidizer-fuel that ignites in said combustion chamber.

In the statorreactors planned for some operations with a low Mach number (for example up to Mach 2), said fuel injection device can be constituted by a set of elementary injectors, arranged on the internal wall of the statorreactor, on the periphery of the jet of oxidizer.

However, for operations with numbers of Mach elevated, when the combustion in the statorreactor is done in a supersonic or hypersonic jet, fuel injection already cannot be done only on the inner wall of the Statorreactor Indeed, in this case, the penetration of fuel jets in the oxidizer jet is too much reduced so that a good mixture of the oxidizer can be obtained and of the fuel inside said jet, so that the Combustion is bad, or even impossible. Naturally said inconvenience is more important the larger the dimensions cross sections of the combustion jet.

Also to remedy it, some are already planned injection devices in the form of ramps, provided with a plurality of elementary injectors distributed along the same, which is disposed in said jet of oxidizer, transversely to it, solidarity with the extremities of said ramps to the opposite walls of said statorreactor, such as describes document US 3 727 409 A. Said injection device It is generally designated by the term "injection post" and is used both in isolation and in combination with an injection of fuel on the wall

Thanks to the injection posts, you can obtain a satisfactory fuel-oxidizing mixture through entire section of the jet of oxidizer. More generally, the injection posts implanted in a hypersonic statorreactor allow:

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secure one fuel supply throughout the combustion jet, to despite the reduced penetration of the fuel jets in a jet of combustion at hypersonic speed;

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increase the proportion of fuel in the oxidizing mixture fuel;

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help on of the combustion-fuel mixture and stabilize the flame;

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participate in the Combustion jet compression, slowing the flow of oxidizer captured by the statorreactor.

Said injection posts, which are subjected to the combustion jet action, therefore behave, each one, from the aerodynamic point of view, like a recessed wing at its ends on two opposite walls of the statorreactor. In addition, on the side of its opposite wheel, to the injectors of fuel arranged in the post socket, which receives the jet of oxidizer, said injection posts must have an edge of attack of a reduced radius so that losses of pressure, which would limit the propulsive actions of the statorreactor and could even lead to a blockage of the jet of oxidizer, which can only become hypersonic in the chamber of combustion if the speed of the oxidizer in the upward direction  It is high enough.

However, the overheating of said wheel, generated by the jet of hypersonic oxidizer, it is so sensitive inversely proportional to the square root of the radius of the leading edge of said wheel. As a result, a wheel with reduced radius of the leading edge is subjected to very important warming. It will also be noted that, being said injection posts arranged inside the Statorreactor, it is impossible to ensure its radiation cooling with the air in which the propelled aircraft flies by said Statorreactor Said wheel is therefore subject to very high temperatures, of the order of 5000 K for an aircraft that Mach 12 flies at an altitude of the order of 30 km. It is therefore it is necessary to build the injection posts in such materials as ceramics, the radius of said leading edge of the order being from 3 to 5 mm. However, considering the procedures current realization of ceramic pieces, it is conceived Easily make material injection poles ceramic, which must satisfy great precision, is necessarily long and expensive.

The present invention is intended to remedy these inconveniences. It refers to an injection post for hypersonic statorreactor, which, at the same time, has an edge of attack with a reduced radius and that can be manufactured in materials other than ceramics.

For this purpose, the injection post of fuel for a statorreactor intended to work with a high Mach number and that involves a combustion chamber in which is introduced a jet of oxidizer, with said post a wheel that has a leading edge that receives said jet of oxidizer and which forms a ramp in the base of said post of elementary fuel injectors, arranged in said jet of oxidizer transversely to it and that distributes said fuel in said jet of oxidizer, it is remarkable, according to the invention, because:

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said roll is formed at least near its leading edge, by a wall permeable, and

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said post behaves:

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a planned camera in the concavity of said permeable wall of the wheel, and

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a means of injection of a cooling fluid in said chamber, being suitable said injection means to generate a plurality of jets of cooling fluid spread along the height of said wheel and hitting the concave face of said wall permeable, at least in the area of said leading edge, so that through said permeable wall.

Thus, a cooling of the edge of post attack by injecting through it a fluid of cooling at the highest speeds. Moreover, said permeability of the leading edge also allows, as will be seen in more detail then facilitate ignition at lower speeds admitting air at lower speeds taking advantage of the permeability "in both directions" of edge of attack.

By way of example, said wall of the wheel can  be carried out, at least near the leading edge of the latter, in a material permeable to the cooling fluid jets, or it can have at least one series of perforations that extend along the leading edge of the wheel, or also to the least one slot that extends along the leading edge of the rue.

Advantageously, the cooling fluid is It consists of fuel.

According to another feature of the invention, said The wheel consists of a dihedral shaped piece whose edge it forms the leading edge of the wheel and defines, in its concavity, a camera.

In addition, the post advantageously comprises a body that defines, inside the injection post, a internal cavity in which a plurality of elementary chambers made, each, in the form of a cylinder perforated open at both ends.

In particular, said elementary chambers are arranged on top of each other and at a certain distance each other, in said cavity, forming a row.

Preferably, a first end of each of said chambers flows into the concavity of said wheel, while than any other end of these cameras, in the socket of the injection post, is made in the form of main injector of  fuel.

According to another feature of the invention, a lid-shaped piece, provided with corresponding holes, It covers the set of the first ends of said chambers. Advantageously, in the post socket, it is provided, in each interval between two elementary chambers, a secondary injector of fuel.

Moreover, the fuel supply of said post can be made through channels of feeding provided at the ends of the post embedded in the opposite walls of the injection chamber of the statorreactor.

In addition, the post can comprise sensors of measuring the pressure at the leading edge, of the interior of the post and the fuel supply pressure, as well as a sensor measuring the temperature of the edge wall of attack.

It will be deduced from the figures in the attached drawing how the invention can be realized. In these figures, references identical designate similar elements.

Figure 1 is a very schematic view in perspective of an exemplary embodiment of a statorreactor provided with fuel injection poles, assuming that the The cover of said statorreactor is transparent.

Figure 2 is a perspective view in explosion of an embodiment of the injection post of fuel according to the present invention.

Figure 3 is a middle longitudinal section of the post of figure 2.

Figures 4, 5, 6, 7 and 8 are sections cross-sections of said fuel injection post, which correspond respectively to the section lines IV-IV, V-V, VI-VI, VII-VII and VIII-VIII of the figure 3.

Figure 9 is a half cross section schematic of a part of an injection post according to the invention in the flow of fuel and oxidizer.

Figure 10 is a half cross section schematic of the injection post part of figure 9 in the engine walls, which presents lateral feeds of fuel.

Figures 11 and 12, analogous to Figure 9, illustrate two modes of operation of the injection post according to the invention.

Statorreactor 1, shown in Figure 1, It is intended for the propulsion of a hypersonic aircraft (not represented) that must fly in a wide range of Mach numbers, for example from about Mach 3 to a Mach number of the order of 12 to fifteen.

Statorreactor 1 has a cover 2 provided, at one of its ends, with an air intake 3 for a air jet that should serve as a oxidizer (symbolized by arrows F) and, at its opposite end, from a nozzle 4. Below the air intake 3, the cover 2 forms an injection chamber 5, inside which two injection posts are arranged fuel 6, transversely to the jet of oxidizer F. Los injection posts 6 each have a rod 7 that has a leading edge 8, which receives said jet of oxidizer and are in solidarity with deck 2, by its 6A and 6B ends fixed on the inner side of two opposite walls 5A and 5B of the chamber of injection 5. Between the injection chamber 5 and the nozzle 4, the cover 2 delimits a combustion chamber 9, in which part upper lighters are provided (not shown). In its rear or socket (that is in front of the camera combustion 9), said injection posts 6 involve ramps longitudinal injection (not visible in figure 1, but represented in figure 3 particularly).

This is how the fuel is distributed throughout the jet of oxidizer F, at the level of injection posts 6, and the combustion of the combustion-fuel mixture flow occurs in the combustion chamber 9, after which the gases of combustion are expelled through the nozzle 4. It will be observed that, as fuel, kerosene can be used for numbers Mach's lowest flight (up to Mach 8) (eventually with a hydrogen wash so that the ignition of the statorreactor and the jet is fired), then hydrogen for higher Mach numbers. They can also be used other fuels, such as methane, endothermic hydrocarbons, synthetic fuels, for a statorreactor of this type.

In the particular embodiment example shown in figure 1, the cover 2 of the statorreactor presents, as a whole, a section duct shape rectangular or square transverse, generally constituted by four opposite walls two to two (which are supposed to be transparent in this figure 1). Of course, such configuration is not limiting absolutely.

As already mentioned above, the edge of attack 8 of the rod 7 of the injection posts 6 supports very important thermal fluxes, when the jet of oxidizer corresponds to a hypersonic flight. So, at Mach 12, the edge of attack of the wheel can be raised to a temperature of the order of 5000K

Figures 2 to 8 illustrate an embodiment for an injection post 6 according to the invention and capable of resist thermal stresses equally high.

As these figures show, in this mode of embodiment, the fuel injection post 6 involves a body 10, in particular metallic, which may be formed, such as Figure 2 illustrates, by two assembled half-bodies 10A, 10B and said wheel 7, can be constituted by a piece, for example metallic, substantially in the form of a dihedral whose edge forms the leading edge 8 of row 7 and defining, in its concavity, a chamber 11. As already indicated, the rod 7 is formed, at least near its leading edge 8, by a wall 12 permeable to jets of cooling fluid.

The latter can be done, at least near the leading edge 8 of the wheel 7, of a material permeable to jets of cooling fluid, that is, in this case, the wall permeability is due to the natural porosity of the material used However, as illustrated in the figures, the wall 12 of row 7 may also have a series of perforations 13, or a groove 13a (in mixed strokes in the figure 2), which extends along the leading edge 8 of row 7. It will be noted that any other device can be provided that allow conferring the desired permeability while retaining the Once enough mechanical stability.

By way of example, knowing that any dimensioning depends of course on the application and the cases particular, typical dimensions, at the level of the wheel can have a thickness of the order of 30 mm, a leading edge radius millimeter, an angle of 6º for the wheel, a length of several tens of centimeters, and an amplitude that can reach 1 m. TO In this regard, the drawings, in particular Figure 2, should not be considered an accurate illustration of this sizing but which have been elaborated rather for clarity of the representation.

Whereas a cooling fluid advantageously it is constituted by the fuel itself, from which it can inject a small part through the leading edge to refrigerate the latter to the highest flying Mach (from Mach 6 for example), the following will be described in detail internal structure of the body 10 of the injection post 6 according to the exemplary embodiment of the invention illustrated by figures 2 to 8.

As seen particularly in Figure 2, the two half bodies 10A, 10B define, inside the post of injection 6, an internal cavity 14 in which a plurality of elementary chambers 15 made, each, under shape of a perforated cylinder open at both ends. The chambers 15 are arranged on top of each other, and at a certain distance from each other, in cavity 14 forming a row and a first end 15A of each of these ends at the concavity of the wheel 7, preferably by means of a corresponding hole 16A of a piece 16, constituting a kind of cover, which covers the set of the ends 15A of the chambers 15. Each of the other ends 15B of the chambers 15 in the post socket of injection 6, is made in the form of a main injector of fuel.

In the socket of the injection post 6, it is on another intended part, in each interval between two cameras 15, a secondary fuel injector 17,

The set is fueled by Feeding channels 18 provided at ends 6A, 6B of post 6 embedded in opposite walls 5A, 5B of the chamber of injection 5. The fuel is distributed in cavity 14, at through the perforated chambers 15, being channeled by longitudinal ribs 19 that define emptying 20 along of the height of the cavity 14.

In addition, Figures 2 and 3 show some shots of pressure 21, while numerical reference 22 designates, in the Figure 3, a support and support plate for cameras 15 (see also figure 5).

Figures 9 and 10 illustrate even the invention according to a simplified embodiment of the injection post 6, which still has a wheel 7 that has a leading edge permeable 8.

The simplified representation of the post injection in figures 9 and 10 makes it possible to make explicit more clearly the two modes of operation authorized by the post structure according to the invention, in relation to the figures 11 and 12 that follow.

On the other hand, figure 9 represents, according to a variant embodiment in relation to figures 2 to 8 but whose principle remains the same, an internal chamber 23 with permeable wall 24. The main fuel injection is performs in the jet through holes 25, an injection secondary through holes 26, said injections being able to be advantageously sonic or supersonic.

In figure 10, feedings are seen with fuel 27, equipped with a pressure adjustment device and flow rate (not shown).

In addition, channel 28 allows communication between the permeable leading edge 8 and the internal chamber 23.

The outer wall of the injection post 6 can be eventually permeable locally (in 29), for example to evacuate, by film effect, excessive local thermal flux, linked to the impact of a crash.

30 tensioners may be necessary for good mechanical stability of the post.

It can be implanted, in the internal chamber, a ignition device 31 (figure 10), constituted for example by one or several electrically operated spark plugs.

In addition, pressure measurements are used to administer the injection according to the desired effect. It is measured, by example, the pressure at the leading edge (sensor 32), the pressure in the internal chamber (sensor 33) and the supply pressure with fuel (sensor 34). If desired, temperature measurement (for example by thermocouple 35) of the leading edge wall can allow cooling of the latter to be activated.

Pole operating mode management Injection is done by playing with:

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Power supply ergoles with a given pressure,

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the use or not of the ignition device,

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from measurements which come from the pressure and temperature sensors.

The direction of the flow (intake of oxidizer, in particular air or injection of cooling fluid, in particular of fuel) through the permeable leading edge of the wheel of the pole - in other words, aspiration in "burner" mode or injection in "leading edge cooling" mode (figures 11 and 12) - advantageously depends on the pressure difference between the outside (incident air) and the inside of the post, unused no particular mobile mechanical organ (such as a valve) at the level of injection post.

It will also be noted that the use of different feeds offers in particular the possibility to adjust more easily the pressure in the internal chamber 23 always injecting the fuel flow required by the engine.

The "burner" mode (figure 11) is used in case of combustion problems, usually with a number Mach reduced supersonic flight, when the stability of the material that constitutes the leading edge 7 of post 6 is not involved This is translated by an air intake (arrow A) to permeable leading edge level (particularly perforated) 8.

A combustion called pilot then has place in internal chamber 23 of post 6 by mixing with the fuel injected (arrows B). At the exit of the post (lower end in relation to air flow), you get then, next to a fuel injection (arrows C), a main injection of burned gases, for example enriched (arrow D).

The main effect of combustion in the chamber pilot 23 is the ignition and combustion stabilization main by creation of a hot jet. When the combustion in the pilot chamber in a subsonic flow and with a constant section, decreases the pressure, which favors the Air penetration through the leading edge.

The wall of the pilot camera is subject to thermal flows, but:

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the pressure on it still reduced, the mixture is rich and the thermal fluxes generated are still reasonable,

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the fuel cools this chamber (which can also be made up of a high temperature resistant material if it were necessary):

one/

by circulation, in particularly in the case where an injection of fuel (arrows C),

two/

by refrigeration parietal (perspiration or effusion) if a technology of permeable wall for the pilot camera, as seen in the figure eleven.

The ignition management is carried out as follows mode.

When the air stop temperature is enough to generate a self-ignition (1000 K with hydrogen for example), it is not necessary to use the ignition device 31.

By cons, when the flight conditions are such that a self-ignition of the mixture in the chamber is not generated pilot, it is necessary to use the ignition device. Yes, for any reason, you want to avoid a power on these conditions, the ignition device control facilitates a degree of additional freedom.

On the other hand, combustion can be performed main behind the injection post in a subsonic flow or supersonic. The air captured by the main air intake prevents injection pole and burns with the fuel remaining in the enriched burned gases (arrow D) and with which it has been injected at the level of arrows C, where appropriate.

Eventually, at least one of the feeds of fuel 27 may allow to inject oxygen or other oxidizer in order, for example, to increase the thrust when the mission need (called statorreactor operation with ejectors).

The "edge cooling of" mode is used attack "(figure 12) when the stability of the material that constitutes the leading edge is involved. As already indicated, this results in an injection of fluid from cooling (in particular of the fuel) through the edge of permeable attack 8 of rod 7 of injection post 6.

Under these conditions, the internal camera only It contains fuel that travels in it before being injected into forward part - - in the direction of the flow of oxidizer - - (to cool the leading edge 8 of row 7 by means of creation of a protective film around it) and partly backwards forming the main fuel injection (arrow D ') and possibly auxiliary injections (arrows C), for a injection and combustion in the engine.

In this case, no combustion takes place in the internal chamber: the air, which had sufficient conditions for a self-ignition then it has a lower pressure than the fuel and therefore cannot penetrate the chamber internal

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By way of illustration, below a numerical example, related to different pressures of the system, for a statorreactor that propels an aircraft that fly from Mach 3 to Mach 15.

Designating (see figure 9) by:

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Pa: the pressure of air behind the right side of the shock given off Ä on the leading edge 8 of the post,

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Pci: the pressure on the internal chamber,

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Pe: the pressure of fuel injection or more generally of ergoles (it is say the injected in the post and regulated, with the losses of load),

I know

will observe what:

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Pa depends on the post shape and aerodynamic conditions incidents

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Pe is set to function of the effect to be obtained and the response of the system,

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Pci is the result of the chosen operation.

Remember that the adjustment parameters main ones are:

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the pressure of power generated by Pe,

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use or not (YES; NO) of the ignition device.

The following table summarizes the orders of magnitude of the pressures obtained in the different elements of the system:

* Pa (bar) Pe (bar) Pci (bar) Mach 3 YES 2.6 two 8 Mach 5 DO NOT 6 4 10 Mach 6 DO NOT 7.5 25 30 Mach 8 DO NOT 9 25 30 Mach fifteen DO NOT 10 40 Four. Five * device use ignition

On the other hand, it is important to take care that the pressure of injection through the main and secondary injectors be higher than the local air pressure and if possible, that the injection conditions are favorable to the mixing of this fluid injected with the air that deviates from the pole.

Often, the need to cool the chamber of combustion, as well as the thrust needs, imply a operation with a fuel flow that increases sharply from Mach 10, which explains the significant increase in Pe, in the previous table, between Mach 8 and Mach 15.

As indicated above, the advantages of Fuel injection post according to the invention are numerous. However, it is particularly suitable for a statorreactor that operate in a wide range of Mach in supersonic and hypersonic and at least partly use a fuel that can present ignition difficulties, such as kerosene. It is also very useful when you want to use supersonic combustion for some Mach flight less than 6 or when, for various reasons, it is a help to the ignition necessary.

The basic idea of the invention is therefore, in addition to cooling the leading edge of the pole of injection by injecting through it a cooling fluid (eg fuel) at the highest speeds (mode "leading edge cooling"), to facilitate ignition at the lowest speeds, by admitting air inside the post ("burner" mode) thus taking full advantage of the double permeability of the leading edge.

It will also be noted that this function is obtained of valve without any mechanical organ at the level of the post injection, simply by managing the differential of pressure between the incident air and the inside of the post.

Claims (14)

1. Fuel injection post (6) for a Statorreactor (1) intended to operate with a Mach number elevated and which involves a combustion chamber (8) in which introduce a jet of oxidizer (F), said post (6) leading a wheel (7) that has a leading edge (8) that receives said jet of oxidizer and forming, in the socket of said post, a elementary fuel injector ramp, arranged in said jet of oxidizer transversely to it and that distributes said fuel in said jet of oxidizer, characterized in that:

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said wheel (7) is formed, at least near its leading edge (8), by a wall (12) in the concavity of which a chamber is arranged (eleven);

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a means of injection (15, 18) are suitable for generating, in said chamber (11), a plurality of jets of a cooling fluid distributed to along said roll (7) and hitting the concave face of said wall (12), at least in the area of said leading edge (8); Y

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said wall (12) is permeable to the jets of cooling fluid that hit it on its concave face, so that said fluid jets of cooling pass through said wall (12).

2. Injection post according to claim 1, characterized in that said wall (12) of the wheel (7) is manufactured, at least near the leading edge (8) of the latter, in a material permeable to the fluid jets of refrigeration. 3. Injection post according to claim 1, characterized in that said wall (12) of the wheel (7) has at least one series of perforations (13) that extend along the leading edge (8) of the wheel ( 7). 4. Injection post according to claim 1, characterized in that said wall (12) of the wheel (7) has at least one groove (13a) extending along the leading edge (8) of the wheel (7) . 5. Injection post according to any one of claims 1 to 4, characterized in that the cooling fluid consists of fuel. 6. Injection post according to any one of claims 1 to 5, characterized in that said wheel (7) is constituted by a substantially dihedral shaped piece whose edge forms the leading edge (8) of the wheel and which defines, in its concavity, a camera (11). 7. Injection post according to claim 5 or 6, characterized in that it comprises a body (10) which defines inside an injection post (6), an internal cavity (14) in which a plurality of elementary chambers ( 15) made, each, in the form of a perforated cylinder open at both ends. 8. Injection post according to claim 7, characterized in that said elementary chambers (15) are arranged one above the other, and at a certain distance from each other, in said cavity (14), and in a row. 9. Injection post according to claim 8, characterized in that a first end (15A) of each of said chambers (15) flows into the concavity of said wheel (7), while any other end (15B) of said chambers ( 15), in the socket of the injection post (6), is carried out in the form of a main fuel injector. 10. Injection post according to claim 9, characterized in that a cover-shaped piece (16), provided with corresponding holes (16A), covers the assembly of the first ends (15A) of said chambers (15). 11. An injection post according to any one of claims 7 to 10, characterized in that, in each interval between two elementary chambers (15), a secondary fuel injector (17) is provided. 12. Injection post according to any one of claims 7 to 11, characterized in that the fuel supply of said post is secured by feeding channels (18) provided at the ends (6A, 6B) of the post (6) embedded in the opposite walls (5A, 5B) of the injection chamber (5) of the statorreactor. 13. Injection post according to any one of claims 1 to 12, characterized in that it comprises sensors (32, 33, 34) for measuring the pressure at the leading edge, that of the inside of the post and the supply pressure made out of fuel. 14. Injection post according to any one of claims 1 to 13, characterized in that it comprises a sensor (35) for measuring the temperature of the leading edge wall.